Drilling apparatus



Aug. 11, 1942. c. L. CHARLES DRILLING APPARATUS Filed Jan. 15, 1940 4 Sheets-Sheet l 1942.- I c. L. CHARLES Q 2 ,292,867

DRILLING APPARATUS Filed 15, 1940 I 4 Sheets-Sheet 2 c. L. CHARLES 2,292,867

DRILLING APPARATUS '4 Sheets-Sheet 3 mimmmmnn 6 4277-1 akar/ea Aug. 11, 1942 j c. CHARLES DRILLING APPARATUS 4 Sheets-Sheet 4 Filed Jan 15, 1940 Inewifi- Car/ l @arkfi,

Patented Aug. 11, 1942 DRILLING APPARATUS Carl L. Charles, Winnetka, Ill., assignor to Gas Tool Patents Corporation, a corporation of Delaware Application January 15, 1940, Serial No. 313,976

6 Claims.

This invention relatesto drilling apparatus, and more particularly to such apparatus making use of an internal combustion motor for deliveringimpacts to the tool.

One feature of this invention is that simple and positive means for rotating the tool during drilling are provided; another feature of this invention is that the tool is rotated automatically during drilling; a further feature of this invention is that means are incorporated, in the connections between the drill-rotating motor and the rotating means, for preventing continued application of the full power of the rotating motor when the tool jams; another feature of this invention is that means is provided for stopping at least one of the motors upon jamming of the tool; still another feature is that all of the elements desirable for deep drilling in rock, for example, are mounted on a, readily movable platform; other features and advantages of this invention will be apparent from the following specification v and the drawings, in which:

Figure 1 is a side elevation of drilling apparatus embodying my invention; Figure 2 is an elevation of the same apparatus; Figure 3 is a top plan view, partly broken away; Figure 4 is a detail sectional view of the lower end of the percussive device; Figure 5 is a sectional view along the line 5-5 of Figure 4; Figure 6 is another view of the lower end of the tool-rotating means; Figure 7 is a view along the line 1'1 of Figure 6; Figure 8 is a detail view, partly in' section, of means for stopping one of the motors upon jamming of the tool; Figure 9 is a detail view, partially in section, of the clutch in the means connecting the tool-rotating motor to the rotating means; and Figure 10 is a schematic wiring diagram of the ignition system of the percussive device.

The apparatus disclosed here comprises a platform or support 20 mounted on Wheels 2|, 22 and 23. The platform has extending upwardly at the front thereof, and pivotally mounted thereon, a rail or channel member 24, adapted to be slidingly engaged by brackets 25 and 2B. These brackets have mounted thereon a percussive device comprising an internal combustion motor 21 adapted to impart impacts to a tool or drill rod 28, and drill-rotating means indicated in general as 29. Means for adjusting the position of the channel member 24 is provided, here shown as rods 30 and 3| with a turn buckle 32 therebetween.

The hammer unit 21 is adapted-to be moved up and down vertically by the sliding cooperation of its supporting brackets with the channel member 24. In order to support it in any desired elevated position, the bracket 25 has movably mounted thereon a latching dog 33 adapted to cooperate with notches 40 in the front of the lower part of the channel member 24.

In order to insure removal of a stuck drill from a hole, means providing considerable leverage for raising the hammer unit is provided. This is here shown in the form of a cable 33 passing over pulleys 34 and 3.5 and connected to .a yoke 36 at the top of the internal combustion hammer sary, to move the hammer upwardly.

.- This is here shown as a small internal combusticn motor 4| of conventional type, directly coupled to pump means for compressing air in the tank 42. Air from this tank is supplied to the lower part of the hammer, and, through a 1 longitudinal bore in the drill 28,,to the hole, the

connection between the tank and the hammer being effected by a flexible hose 43."

The internal combustion motor in the percussive hammer 21, however, is of the free piston -;.type, rather than of the conventional flywheel and crankshaft type. In this type of motor the piston is driven downwardly, on the two-stroke cycle principle, by the combustion of an explosive thereabove each time it reaches thetop of its ;stroke; and it is returned aftereach power stroke by a spring. The general construction and operation of internal combustion percussive hammers of this type is shown in a number of issued patents, as for example, Mouldv Patent 1,997,070;

and its general operation will, therefore, not be described here.

The internal combustion engine 4 as has been mentioned heretofore, is connected to the drillrotating means indicated in general as 29. This connection is effected through a clutch 44 and a flexible shaft 45. Referring more particularly to Figures 4 and 5, it will be seen that the flexible shaft 45 drives a worm 46 in the tool-rotating means. This worm meshes with a worm gear 41 to rotate the sleeve 48 which has a polygonal internal bore'adapted to permit the tool 28 to have longitudinal but not rotative movement with respect thereto. The worm gear is held in place in the desired operative relation to the worm 46 by a recoil spring 49 operating against annular followers 50 and 5!. The lower follower 5Q presses against the top of the worm gear 41; and the upper follower 5| against a shoulder in the lower or continuation part of th cylinderof the hammer. This upper follower is adapted to make a relatively tight seal with the walls against which its exterior bears, and with the sleeve 48.

The lower or extension portion of the cylinder of the hammer has slidably mounted therein an anvil 52 having thereon sealing rings 53, The

anvil is provided with a transverse bore 54 below two of the sealing rings 53, which communicates with the compressed air hose 43 and with a central bore 55 communicating in turn with the longitudinal bore 56 in the drill 28. Effective sealing of the compressed air from the space above the anvil is necessary in an internal combustion hammer of the free piston type. Compressed air leaking past the anvil upwardly would make it impossible for the piston to draw in a fresh charge, and thus permit proper operation of the hammer. The seal on both sides'of the follower and the close engagement between the bottom of the anvil and top of the wall insures practically all of the compressed air passing. downwardly through thelongitudinal bore 56in the drill, to secure the .desiredblowing of-chips from the bottom ofthe drill hole.

Means for. holding the drill in place as the percussive unit is raisedis, of course,provided. This is here shown as ,a tool holder 5! swingably mounted on a depending vertical rod 58, and adaptedlto be held in tool-holding position by pins, as.59, or swung to one side tolpermit removal or replacement of the tool.

Referring now more particularly'to Sheets 1 and 2 of the application, it willbe seen that driving of the flexible'shaft 45 is efiectedonly when the clutch 44 is engaged. This clutch has an outer or drum portion BK adapted to be engaged by shoes Stand 62; These shoes are held togethenout of engagement with the drum, by springs. 63 until the motor 4| hasreached an effective. operative speed; Centrifugal force then throwsthese shoes out into engagement with the drum fifl; and action of the toggle parts 54 serves to tighten the driving engagement. Whenever the.tool.jams and the flexible shaft 45 ceases rotating,,however, slowing down of the motor automatically throws outthe engagement of the clutch, theshoesfil and BZ-being pulledinwardly by the springs 53' when the rate of-rotation is undesirably slow. This'prevents continued application of the power of the rotating motor to the drill when the drill jams, a particularly important feature Werethis not 'effected' automatically the rotating. partsin thehammer, the flexible shaft, and the like, would all be unduly strained and injured whenever the tool jammed; and the driving motorwould be stalled, making it inconveniently necessary to restart this motor.

In order to prevent continued pounding on the drill when it is not rotating, and -thus obviate stuck drills, I have provided means for automatically stoppingthe drilling motor when the tool jams. .Referringflrst totheschematic diagram in Figure 10, it will be seen that the primary side of the ignition circuit of the hammer is completed through the breaker points 66 and 61 (actuatedby cam means-which actually oscillates a plunger, although this is here shown schematically as a conventional cam), through the switch 68 mounted onthe hammer, and through a switch GQ-adaptedto be automatically operated when the tool speed drops below a predetermined point. This;switch"69, as may be seen in Figure 2, is mounted on the carriage 20 in such a way that its operating lever 10 is engaged by an annulus ll adapted tobe moved longitudinally of the flexible shaft 45 by flyball means 12. As may be best seen in Figure 8, when the flexibleshaft 45 (and thus the tool) is being rotated at a desired rate, the fly-ball governor arrangement holds the annulus H to the left against the tension of the spring 13, keeping the switch 69 in closed position. If the tool jams, however, the cessation of rotation of the flexible shaft lets the spring 13 move the annulus H to the right, and the switch 69 then opens automatically to break the hammer ignition circuit. In order to permit starting of the drilling hammer when the tool is not rotating, a manual switch 14 is provided in shunt with the automatic switch 69.

While I have .shown and described certain embodiments of my invention, it is to be understood that it is capable of-many modifications. Changes, therefore, in the construction and arrangement may be made'wit-hout departing from thespirit and scope of the invention as disclosed in the appended claims.

I claim:

1. Drilling apparatus of the character described, including; a percussive unit including a tool, an internalcombustion '-motor' having a piston reciprocable therein andadapted to impart periodic impacts to the tool, and means for rotating. the tool; a second motor, spaced from the percussive unit, for driving the rotating means; and operative connections between the second motor and the rotating means, including a flexible shaft and a clutch designed to release upon jamming of the tool.

2. Apparatus of the character claimed in claim 1, wherein the second motor. is an internal combustion motor.-

3. Drilling apparatus of the character described-including; a percussive unit including a tool, an internal combustion motor having a piston reciprocable therein and adapted-to impartv periodic impacts to the tool, and means for rotating the tool; a second internal combustion motor, .spaced from the, percussive unit, for

scribed, including: a percussive unit includinga tool, aninternal combustion motor having a pistonreciprocabletherein and adapted to im-- part periodic impactsto the tool, and means for rotating the tool; a second-motor, spaced fromthe percussive. unit, for driving the rotating meanspand .means responsive to resistance ofthe tool to vrotationfor automatically stopping the first mentioned motor when-the tool jams.

5. Apparatus of the character claimed in claim 3, including a readily movable support carrying all .of said elements.-

6. Apparatus of the character claimed" in claim 4, includinga readily movable support car'- rying all ofv said elements.

CARL L. CHARLES? 

